Scaffolds have been used extensively in the area of tissue engineering either to construct a neo tissue that can be implanted to repair a defect site in the body or as a cell container in bioartificial devices. Scaffolds form a three dimensional matrix that serves as a template for cell proliferation and, ultimately, tissue formation.
Culturing cells in a scaffold typically involves seeding cells throughout the scaffold and allowing the cells to proliferate in the scaffold for a predetermined amount of time. A lot of research efforts have been directed at the design fabrication and choice of materials in developing a scaffold for tissue engineering applications. However, the eventual success of a scaffold will be determined by whether the scaffold is able to support cell viability and by its ability to integrate with the host tissues for implantable scaffolds. Hence, the optimization of cell seeding and culture technologies are equally important determinants in the success of a scaffold system.
One method of cell seeding uses the interfacial polyelectrolyte complexation (IPC) technique. Polyelectrolyte complexation is a chemical phenomenon that involves the formation of electrostatic bonds between two polyelectrolytes of opposite charges, leading to a stable macromolecular complex. In fiber formation using the IPC process, a fiber is drawn from the interface between two oppositely charged polyelectrolytes, where local complexation occurs. During this process, the two water-soluble polyelectrolytes become insolubilized in the form of a polyelectrolyte-complex fiber. The mechanism of fiber formation involves the coalescence of fibers in the 100 nm range to form a thicker fiber. Unlike conventional scaffold-formation processes that involve high temperatures, solvents and expensive equipment, polyelectrolyte complexation presents a simple, room-temperature and water-based process. Scaffolds constructed from the polyelectrolyte-complex fibers have been used to encapsulate and immobilize proteins, and to encapsulate cells. However, there is a lack of simple devices for use in a lab setting to form fibers.
Furthermore, current IPC fiber drawing techniques are batch processes whereby fibers are drawn from discrete droplets of polyelectrolytes having cells therein. Hence, the fiber drawing would stop once the polyelectrolyte in one of the droplets is used up. In addition, fibers drawn using the current methods do not have uniform diameters. There is also limited control over the fiber diameter when the current techniques are used. The amount of cells encapsulated within the drawn fibers also lack uniformity.
There is therefore a need to provide improved devices and methods suitable to overcome at least some of the above mentioned disadvantages.